[Technical Field]
[0001] The present invention relates to a positive-type photosensitive resin composition,
a cured product of the positive-type photosensitive resin composition, an interlayer
insulating film, a cover coat layer, or a surface protection film using the cured
product, an electronic component comprising the same, and a method of manufacturing
a pattern cured film.
[Background Art]
[0002] Heretofore, polyimide or polybenzoxazole having all of satisfactory heat resistance,
electric properties, mechanical properties, and the like has been used for a surface
protection film and an interlayer insulating film of a semiconductor device. In recent
years, a photosensitive resin composition obtained by giving photosensitive properties
to the above resins themselves has been used. Thus, a manufacturing process of a pattern
cured film can be simplified, and a complicated manufacturing process can be shortened.
[0003] In the manufacturing process of a pattern cured film, an organic solvent such as
N-methylpyrrolidone has been used in a development step. However, due to an environmental
consideration, there has been suggested a resin composition that can be developed
with an alkaline aqueous solution by a method in which a naphthoquinonediazide compound
is mixed in a polyimide precursor or a polybenzoxazole precursor as a photosensitive
agent (e.g., PATENT LITERATURES 1 and 2).
[0004] Meanwhile, in recent years, miniaturization of transistors that have supported the
enhancement of performance of computers is facing the limit of scaling laws, and it
is considered that technology of three-dimensionally stacking semiconductor elements
is required for higher performance and higher speeds. Against this background, there
has been suggested a three-dimensional package using a through silicon via (TSV),
a 2.5-dimensional package using an interposer, or a 2.1-dimensional package, and stacked
device structures typified by the above have been attracting attention (e.g., NON
PATENT LITERATURE 1).
[0005] Among the stacked device structures, multi-die fanout wafer level packaging is a
package manufactured by collectively sealing a plurality of dies in one package, and
has been attracting much attention because lower cost and higher performance can be
expected than in a conventional fanout wafer level package manufactured by sealing
one die in one package.
[0006] However, in the manufacture of a multi-die fanout wafer level package, a heat treatment
at more than 200°C cannot be conducted from the viewpoint of protecting a high-performance
die, protecting a sealing material having low heat resistance, and improving yield.
Thus, low-temperature curability is strongly demanded even for a polybenzoxazole precursor
used as a rewiring formation layer for rewiring of copper (PATENT LITERATURE 3).
[0007] Even in the case of low-temperature curing at 200°C or less, properties equal to
or more than those at high-temperature curing are required for the rewiring formation
layer. Specifically, in addition to having high resolution in order to perform fine
patterning, having high chemical resistance and high adhesion properties is required.
[0008] Chemical resistance is needed to comply with a plating process of copper rewiring
during multi-die fanout package production. Specifically, in a plating process, after
copper plating using a resist for plating production, a resist stripping solution
which is a strong chemical is used to remove the resist, and resistance to this chemical
is required. Adhesion properties (properties of adhesion between the rewiring of copper
and the rewiring formation layer) are extremely important from the viewpoint of ensuring
reliability.
[0009] However, for the conventional resin composition for the rewiring formation layer
(a positive-type photosensitive resin composition using a polybenzoxazole precursor),
it is difficult to have high chemical resistance and adhesion properties when cured
at a low temperature, and it has been impossible to comply with the production of
the package.
[0010] PATENT LITERATURE 4 discloses that high sensitivity and high resolution are achieved
by combining a specific crosslinking agent and a photosensitive agent with a polybenzoxazole
precursor, but the properties of a cured film at low-temperature curing are low.
[0011] PATENT LITERATURE 5 describes a phenolic resin composition which is high in reliability
even if being applied to a semiconductor and cured by heat at ≤250°C, and can become
an alternative material to polyimide resins and polybenzoxazole resins. The phenolic
resin composition includes a phenolic resin and a solvent, wherein the average tensile
elongation of a cured material thereof measured under specific conditions is ≥20%.
[0012] PATENT LITERATURE 6 describes a photosensitive resin composition which comprises
a polybenzoxazole precursor, a photosensitive agent, a solvent and at least one compound
selected from a group consisting of a heterocyclic compound, thiourea and a compound
having a mercapto group.
[0013] PATENT LITERATURE 7 describes a photosensitive resin composition which contains a
polybenzoxazole precursor, a photosensitizing agent and a solvent.
[0014] PATENT LITERATURE 8 describes a positive photosensitive resin composition which a
polybenzoxazole or a polymer serving as a precursor thereof, a compound generating
an acid when irradiated with an active ray, and a compound having a structure which
is crosslinkable or polymerizable with the polybenzoxazole or polymer by heat.
[0015] PATENT LITERATURE 9 describes a positive photosensitive resin composition which contains
an aqueous alkali solution-soluble polyamide having the structure of a polyoxazole
precursor, an o-quinone diazide compound and a thermal acid generator which generates
an acid when heated. The positive photosensitive resin composition may further contain
a compound having a phenolic hydroxyl group and a solvent.
[0016] PATENT LITERATURE 10 describes a photosensitive resin composition which comprises
an alkali-soluble resin, a photoacid generator, a fluorine-containing copolymer, a
silicon compound (D), and a solvent (E).
[0017] PATENT LITERATURE 11 describes an alkali-soluble resin which contains no halogen
atom in the molecule, has high sensitivity, and attains a wide margin of film thickness
in pattern formation conducted using the same exposure amount and the same development
period. The resin can be developed with the developing solution in general use in
semiconductor device production steps (2.38% aqueous TMAH solution), is soluble in
γ-butyrolactone, and is suitable for use in photosensitive resin compositions.
[0018] PATENT LITERATURE 12 describes a novel alkali-soluble resin which can be used in
a photosensitive resin composition to impart high sensitivity to the composition,
enables the formation of a pattern with a developing solution (an aqueous 2.38 wt%
tetramethylammonium hydroxide solution) that is normally used in the process for producing
a semiconductor device, and can be cured into a heat-resistant film having excellent
mechanical strength, in other words, has a high glass transition temperature and enables
a relief pattern to have excellent solubility in propylene glycol monomethyl ether
after development.
[0019] PATENT LITERATURE 13 describes a photosensitive resin composition which contains
a hydroxy polyamide resin and a photoacid generator, and which has high film retention
ratio after development and high sensitivity, while exhibiting high elongation degree
and high storage stability.
[0020] PATENT LITERATURE 14 describes an alkali-soluble polymer having a low curing shrinkage,
a photosensitive resin composition excellent in a pattern profile after curing, and
a method for producing a cured relief pattern using the composition, and a semiconductor
device and a light emitting device having the cured relief pattern. The alkali-soluble
polymer includes: a structure synthesized from at least one kind of carboxylic acid
compound selected from a group composed of polyvalent carboxylic acids and their derivatives,
and a polyvalent amino compound; and a crosslinking group-containing structure having
a crosslinking group and derived from a compound that can react with the polyvalent
carboxylic acid or its derivative.
[Citation List]
[Patent Literature]
[Non Patent Literature]
[Summary of Invention]
[0023] An object of the present invention is to provide a positive-type photosensitive resin
composition which has satisfactory chemical resistance even when cured at a low temperature
of 200°C or less.
[0024] As a result of repeated intensive studies in view of the above problems, the present
inventors found that a combination of a particular photosensitive agent and a particular
polybenzoxazole precursor exhibited satisfactory chemical resistance even when cured
at a low temperature. The present invention provides a positive-type photosensitive
resin composition comprising a (a) polybenzoxazole precursor, a (b) crosslinking agent,
a (c) photosensitive agent, and a (d) solvent, wherein
the (a) polybenzoxazole precursor comprises a structure represented by Formula (1)
below,
the (b) crosslinking agent is represented by Formula (3) below, and
the (c) photosensitive agent is a compound comprising a structure represented by Formula
(2) below:
(in Formula (1), U is a bivalent organic group, a single bond, -O-, or -SO
2-, V is a group comprising an aliphatic straight-chain structure, and the carbon number
in the aliphatic straight-chain structure is 5 to 10)
(in Formula (3), R
3 is independently a hydrogen atom or -CH
2-O-R
4, and at least one of the plurality of R
3s is -CH
2-O-R
4. R
4 is independently a hydrogen atom, a methyl group, an ethyl group, or a butyl group).
[0025] It further provides embodiments thereof in appended claims 2 and 3.
[0026] It also provides a method of manufacturing a pattern cured film, comprising:
coating the positive-type photosensitive resin composition on a substrate, drying
the positive-type photosensitive resin composition, and thereby forming a photosensitive
resin film;
exposing the photosensitive resin film to a predetermined pattern;
developing the exposed photosensitive resin film by use of an alkaline aqueous solution,
and thereby forming a pattern resin film; and
heat-treating the pattern resin film.
[0027] An embodiment thereof is described in claim 5. It further provides cured products
as claimed in claims 6 and 7 and an electronic component as claimed in claim 8.
[Brief Description of Drawing]
[0028]
FIG. 1 is a schematic sectional view illustrating a part of a manufacturing process
of a fanout package having a multilayer wiring structure;
FIG. 2 is a schematic sectional view illustrating a part of the manufacturing process
of the fanout package having the multilayer wiring structure;
FIG. 3 is a schematic sectional view illustrating a part of the manufacturing process
of the fanout package having the multilayer wiring structure;
FIG. 4 is a schematic sectional view illustrating a part of the manufacturing process
of the fanout package having the multilayer wiring structure;
FIG. 5 is a schematic sectional view illustrating a part of the manufacturing process
of the fanout package having the multilayer wiring structure;
FIG. 6 is a schematic sectional view illustrating a part of the manufacturing process
of the fanout package having the multilayer wiring structure;
FIG. 7 is a schematic sectional view illustrating a part of the manufacturing process
of the fanout package having the multilayer wiring structure; and
FIG. 8 is a schematic sectional view of a fanout package having an under bump metal
(UBM) free structure.
[Description of Embodiments]
[0029] Hereinafter, an embodiment of the present invention is described in detail. However,
the present invention is not limited to the following embodiment. It is to be noted
that in the present description, when "A or B" is mentioned, one of A and B has only
to be included, or both A and B may be included. Further, in the present description,
the term "step" includes not only an independent step, but also a step as long as
a desired action of this step is achieved even when this step cannot be clearly distinguished
from other steps. A numerical range indicated by use of "to" refers to a range including
numerical values described before and after "to" as minimum and maximum values, respectively.
Moreover, in the present description, the content of each component in a composition,
when a plurality of substances corresponding to each component are present in the
composition, means the total amount of the plurality of substances present in the
composition, unless otherwise specified. In addition, unless otherwise specified,
the illustrated materials may be used singly or may be used in combination of two
or more kinds.
[Positive-type photosensitive resin composition]
[0030] The positive-type photosensitive resin composition according to the present invention
comprises a (a) polybenzoxazole precursor, a (b) crosslinking agent, a (c) photosensitive
agent, and a (d) solvent, wherein the (a) polybenzoxazole precursor comprises a structure
represented by Formula (1) below, the (b) crosslinking agent is represented by Formula
(3) below, and the (c) photosensitive agent is a compound comprising a structure represented
by Formula (2) below:
(in Formula (1), U is a bivalent organic group, a single bond, -O-, or -SO
2-, V is a group comprising an aliphatic straight-chain structure, and the carbon number
in the aliphatic straight-chain structure is 5 to 10)
(in Formula (3), R
3 is independently a hydrogen atom or -CH
2-O-R
4, and at least one of the plurality of R
3s is -CH
2-O-R
4; R
4 is independently a hydrogen atom, a methyl group, an ethyl group, or a butyl group).
[0031] By comprising the above components, the positive-type photosensitive resin composition
according to the present invention can form a pattern cured film having high chemical
resistance equal to or more than that of a pattern cured film obtained at high-temperature
curing, even when cured at a low temperature of 200°C or less. Moreover, the positive-type
photosensitive resin composition according to the present invention can form, with
high sensitivity, a pattern having high resolution, and has satisfactory properties
of adhesion to copper or the like. Thus, the positive-type photosensitive resin composition
according to the present invention is suitably applicable to the production of a stacked
device structure typified by a multi-die fanout wafer level package.
[0032] Each component is described below. Hereinafter, the (a) polybenzoxazole precursor,
the (b) crosslinking agent, the (c) photosensitive agent, and the (d) solvent may
be referred to as a (a) component, a (b) component, a (c) component, and a (d) component,
respectively.
((a) component: polybenzoxazole precursor)
[0033] The polybenzoxazole precursor is preferably a material having high transmittance
of a light source (i-line) for use in patterning and showing high cured film properties
even when cured at a low temperature of 200°C or less. Thus, the polybenzoxazole precursor
preferably comprises a structure represented by Formula (1) above.
[0034] V in Formula (1) is a group comprising an aliphatic straight-chain structure. The
carbon number of the aliphatic structure is 5 to 10.
[0035] V is preferably a structure derived from dicarboxylic acid. The raw material dicarboxylic
acid giving V includes dodecanedioic acid, decanedioic acid, nonanedioic acid, cyclohexanedicarboxylic
acid, 2,2-bis (4-carboxyphenyl)-1,1,1,3,3,3-hexafluoropropane, 5-tert-butylisophthalic
acid, and the like. Particularly, from the viewpoint of achieving both ensuring of
i-line transmittance and properties of the elongation at break of a cured film, dodecanedioic
acid or decanedioic acid is preferable as a raw material dicarboxylic acid.
[0036] The polybenzoxazole precursor which is the (a) component may have, in a part thereof,
a structural unit other than the structural unit represented by Formula (1). In this
case, the proportion of the structural unit represented by Formula (1) to all the
structural units is preferably 50 mol% or more, and more preferably 60 mol% or more.
[0037] The structural unit other than the structural unit represented by Formula (1) includes,
a structural unit in which V is a skeleton derived from a diphenylether compound,
and the like, for example, in Formula (1).
[0038] U is preferably a group comprising a structure represented by Formula (u-1) below.
[0039] In Formula (u-1), R
1 and R
2 are independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6
carbon atoms, or a fluorinated alkyl group having 1 to 6 carbon atoms, and a is an
integer of 1 to 30.
[0040] R
1 and R
2 specifically include a methyl group, a trifluoromethyl group, and the like. From
the viewpoint of the transparency of the polybenzoxazole precursor, a trifluoromethyl
group is preferable. a is preferably an integer of 1 to 5.
[0041] Polybenzoxazole is obtained by the hydration and ring closure of the above polybenzoxazole
precursor.
[0042] The above polybenzoxazole precursor is usually developed with an alkaline aqueous
solution. Therefore, the polybenzoxazole precursor is preferably soluble in the alkaline
aqueous solution. The alkaline aqueous solution includes an organic ammonium aqueous
solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, a metal
hydroxide aqueous solution, an organic amine aqueous solution, and the like. In general,
a TMAH aqueous solution having a concentration of 2.38 mass% is preferably used. That
is, the (a) component is preferably soluble in the TMAH aqueous solution.
[0043] Incidentally, one standard for the (a) component to be soluble in the alkaline aqueous
solution is described below. After the (a) component is dissolved into a given solvent
resulting in a solution, a substrate such as a silicon wafer is spin-coated with the
solution to form a resin film having a thickness of 5 µm. This resin film is dipped
in any one of the tetramethylammonium hydroxide aqueous solution, the metal hydroxide
aqueous solution, and the organic amine aqueous solution at 20 to 25°C. When dissolved
and resulting in a solution, the (a) component used is determined to be soluble in
the alkaline aqueous solution.
[0044] The molecular weight of the (a) component preferably has a weight average molecular
weight of 10,000 to 100,000 in terms of polystyrene, more preferably 15,000 to 100,000,
and further preferably 20,000 to 85,000. When the weight average molecular weight
of the (a) component is 10,000 or more, there is a tendency that suitable solubility
into an alkaline developing solution can be ensured. Moreover, when the weight average
molecular weight of the (a) component is 100,000 or less, there is a tendency that
satisfactory solubility into a solvent is obtained, and there is a tendency that deterioration
of handleability resulting from increased viscosity of the solution can be suppressed.
[0045] Further, dispersity in which the weight average molecular weight is divided by a
number average molecular weight is preferably 1 to 4, and more preferably 1 to 3.
[0046] The weight average molecular weight can be measured by gel permeation chromatography,
and can be found by conversion using a standard polystyrene calibration curve.
((b) component: crosslinking agent)
[0047] The (b) component causes a reaction (crosslinking reaction) with the polybenzoxazole
precursor which is the (a) component in a step of heat-treating a pattern resin film
obtained by coating, exposing, and developing the positive-type photosensitive resin
composition. Alternatively, the crosslinking agent which is the (b) component can
be polymerized. Thus, even when the positive-type photosensitive resin composition
is cured at a relatively low temperature of, for example, 200°C or less, it is possible
to provide satisfactory mechanical properties, such as chemical resistance and adhesion
properties.
[0048] From the viewpoint of a low reaction temperature, a compound represented by Formula
(3) below is used:
(in Formula (3), R
3 is independently a hydrogen atom or -CH
2-O-R
4, and at least one of the plurality of R
3s is -CH
2-O-R
4. R
4 is independently a hydrogen atom, a methyl group, an ethyl group, or a butyl group).
[0049] It is preferable that 2 to 6 of the plurality of R
3s are -CH
2-O-R
4, and it is more preferable that all of R
3s are -CH
2-O-R
4. R
4 is preferably a methyl group.
[0050] A compound represented by Formula (4) below is the most preferable. With this compound,
a cured film having satisfactory chemical resistance and adhesion properties is obtained
when the positive-type photosensitive resin composition is cured at a low temperature
of 200°C or less.
[0051] The content of the (b) component in the positive-type photosensitive resin composition
according to the present invention is preferably 1 to 50 parts by mass with respect
to 100 parts by mass of component (a), more preferably 5 to 30 parts by mass in order
to ensure satisfactory mechanical properties, and further preferably 10 to 30 parts
by mass from the viewpoint of achieving both mechanical properties and photosensitive
properties.
((c) component: photosensitive agent)
[0052] The positive-type photosensitive resin composition according to the present invention
comprises, as the (c) component, a compound (diazonaphthoquinone compound) comprising
a structure represented by Formula (2) below.
[0053] The (c) component is preferably represented by the Formula (2') below.
(in Formula (2'), n is an integer of 1 to 4. X is an a monovalent to tetravalent residue
of a hydroxy-group-containing compound, or a monovalent to tetravalent residue of
an amino-group-containing compound.)
[0054] The residue of the hydroxy-group-containing compound refers to a group obtained by
removing a hydrogen atom of a hydroxy group from the compound. The residue of the
amino-group-containing compound refers to a group obtained by removing a hydrogen
atom of an amino group from the compound.
[0055] X in Formula (2') is preferably represented by Formula (11) below.
[0056] In Formula (11), R
11 and R
12 are independently represented by a hydrogen atom, an alkyl group having 1 to 6 carbon
atoms, a fluorinated alkyl group having 1 to 6 carbon atoms, or a group represented
by Formula (12) below.
[0057] In Formula (12), R
13 and R
14 are independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or
a fluorinated alkyl group having 1 to 6 carbon atoms.
[0058] In Formulas (11) and (12), * is a position to bond with the structure within the
brackets of Formula (2'). It is only necessary to bond with the structure in at least
one *, or it is possible to bond with the structure in all *s.
[0059] The compound represented by Formula (2) is obtained by, for example, causing a condensation
reaction between 1,2-naphthoquinone-2-diazide-4-sulfonyl chloride, and a hydroxy-group-containing
compound, an amino-group-containing compound, or the like, in the presence of a dehydrochlorination
agent.
[0060] The hydroxy-group-containing compound is not particularly limited, but from the viewpoint
of enhancing a dissolution inhibiting effect in unexposed parts, is preferably hydroquinone,
resorcinol, pyrogallol, bisphenol A, bis (4-hydroxyphenyl) methane, 2,2-bis (4-hydroxyphenyl)
hexafluoropropane, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone,
2,2',4,4'-tetrahydroxybenzophenone, 2,3,4,2',3'-pentahydroxybenzophenone, 2,3,4,3',4',5'-hexahydroxybenzophenone,
bis (2,3,4-trihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) propane, 4b,5,9b,10-tetrahydro-1,3,6,8-tetrahydroxy-5,10-dimethyl-indeno
[2,1-a] indene, tris (4-hydroxyphenyl) methane, and tris (4-hydroxyphenyl) ethane.
[0061] As the amino-group-containing compound, it is possible to use p- phenylenediamine,
m-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone,
4,4'-diaminodiphenylsulfide, o-aminophenol, m-aminophenol, p-aminophenol, 3,3'-diamino-4,4'-dihydroxybiphenyl,
4,4'-diamino-3,3'-dihydroxybiphenyl, bis (3-amino-4-hydroxyphenyl) propane, bis (4-amino-3-hydroxyphenyl)
propane, bis (3-amino-4-hydroxyphenyl) sulfone, bis (4-amino-3-hydroxyphenyl) sulfone,
bis (3-amino-4-hydroxyphenyl) hexafluoropropane, and bis (4-amino-3-hydroxyphenyl)
hexafluoropropane.
[0062] 1,2-naphthoquinone-2-diazide-4-sulfonylchloride, and the hydroxy-group-containing
compound or the amino-group-containing compound are preferably blended so that the
sum of the hydroxy group and the amino group is 0.5 to 1 equivalent of 1 mole of naphthoquinone-1,2-diazide-4-sulfonyl
chloride.
[0063] A preferred ratio (molar ratio) between the dehydrochlorination agent and 1,2-naphthoquinone-2-diazide-4-sulfonylchloride
ranges from 0.95/1 to 1/0.95. A preferred reaction temperature is 0 to 40°C. A preferred
reaction time is 1 to 10 hours.
[0064] As a reaction solvent for the above reaction, it is possible to use dioxane, acetone,
methyl ethyl ketone, tetrahydrofuran, diethyl ether, N-methylpyrrolidone, or the like.
[0065] As the dehydrochlorination agent, it is possible to use sodium carbonate, sodium
hydroxide, sodium hydrogen carbonate, potassium carbonate, potassium hydroxide, trimethylamine,
triethylamine, pyridine, or the like.
[0066] As the (c) component, it is particularly preferable to use a compound represented
by Formula (5) below from the viewpoint of higher sensitivity and higher resolution.
(in Formula (5), Q is independently a hydrogen atom or a group represented by Formula
(6) below. At least one Q is a group represented by Formula (6) below)
[0067] The content of the (c) component in the positive-type photosensitive resin composition
according to the present invention needs only to be suitably adjusted in consideration
of dissolution contrast and the like. However, especially in the case of a thick film,
the diazonaphthoquinone compound itself has absorption for the i-line, so that when
the (c) component is blended in a large amount, the i-line does not reach the bottom
of the film, photoreaction becomes difficult due to insufficient exposure to the diazonaphthoquinone
compound, and there is concern that an opening pattern cannot be formed. Accordingly,
the (c) component is preferably 1 to 20 parts by mass with respect to 100 parts by
mass of the (a) component, and more preferably 5 to 15 parts by mass.
[0068] Further, the (c) component is preferably highly compatible with the (a) component
from the viewpoint of film formability and higher sensitivity.
((d) component: solvent)
[0069] The (d) component includes γ-butyrolactone, ethyllactate, propyleneglycolmonomethyletheracetate,
benzylacetate, n-butylacetate, ethoxyethylpropionate, 3-methylmethoxypropionate, N-methyl-2-pyrrolidone,
N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphorylamide,
tetramethylenesulfone, cyclohexanone, cyclopentanone, diethylketone, diisobutylketone,
methylamylketone, and the like. Normally, the (d) component is not particularly limited
as long as other components in the photosensitive resin composition can be sufficiently
dissolved.
[0070] Among the above, from the viewpoint of satisfactory solubility of each component
and coating properties at the time of resin film formation, it is preferable to use
γ-butyrolactone, ethyllactate, propyleneglycolmonomethyletheracetate, N-methyl-2-pyrrolidone,
N,N-dimethylformamide, N,N-dimethylacetamide, or dimethylsulfoxide.
[0071] The content of the (d) component in the positive-type photosensitive resin composition
according to the present invention is not particularly limited, but is preferably
50 to 300 parts by mass with respect to 100 parts by mass of the (a) component, and
more preferably 100 to 200 parts by mass.
[0072] The positive-type photosensitive resin composition according to the present invention
may consist essentially of the (a), (b), (c), and (d) components. For example, 80
mass% or more, 90 mass% or more, 95 mass% or more, or 98 mass% or more of the positive-type
photosensitive resin composition according to the present invention may be the above
(a), (b), (c), and (d) components. Alternatively, the positive-type photosensitive
resin composition according to the present invention may consist of the (a), (b),
(c), and (d) components alone. In this case, the composition may comprise inevitable
impurities.
[0073] In addition to the above (a) to (d) components, the resin composition according to
the present invention may comprise, if necessary, (1) a coupling agent, (2) a dissolution
accelerator, (3) a dissolution inhibitor, and (4) an interfacial active agent, a leveling
agent, or the like.
((1) coupling agent)
[0074] It is estimated that a coupling agent (compound different from the above (b) crosslinking
agent) usually reacts to and thus crosslinks with the polybenzoxazole precursor which
is the (a) component in the step of heat-treating after coating, exposing, and developing
the positive-type photosensitive resin composition, or a coupling agent itself is
polymerized in the step of heat-treating. Thus, it is possible to further improve
the properties of adhesion between a cured film to be obtained and the substrate.
[0075] In the present invention, by using a silane coupling agent having a urea bond (-NH-CO-NH-)
in a molecule in addition to the composition according to the present invention, it
is possible to further increase the properties of adhesion to the substrate even when
curing is conducted at a low temperature of 200°C or less.
[0076] A preferred silane coupling agent includes a compound having a urea bond. For satisfactory
development of adhesion properties when curing is conducted at a low temperature,
a compound represented by the Formula (7) below is more preferable.
(in the formula, R
5 and R
6 are independently an alkyl group having 1 to 5 carbon atoms. a is an integer of 1
to 10, and b is an integer of 1 to 3).
[0077] Specific examples of the compound represented by formula (7) include ureidomethyltrimethoxysilane,
ureidomethyltriethoxysilane, 2-ureidoethyltrimethoxysilane, 2-ureidoethyltriethoxysilane,
3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 4-ureidobutyltrimethoxysilane,
4-ureidobutyltriethoxysilane, and the like. 3-ureidopropyltriethoxysilane is preferable.
[0078] Further using a silane coupling agent having a hydroxy group or a glycidyl group
in a molecule in addition to the above-described silane coupling agent having a urea
bond in a molecule is effective in further improving properties of adhesion of the
cured film to the substrate at low-temperature curing.
[0079] The silane coupling agent having a hydroxy group or a glycidyl group in a molecule
includes methylphenylsilanediol, ethylphenylsilanediol, n- propylphenylsilanediol,
isopropylphenylsilanediol, n-butylphenylsilanediol, isobutylphenylsilanediol, tert-butylphenylsilanediol,
diphenylsilanediol, ethylmethylphenylsilanol, n-propylmethylphenylsilanol, isopropyl-methylphenylsilanol,
n-butylmethylphenylsilanol, isobutylmethylphenylsilanol, tert-butylmethylphenylsilanol,
ethyln-propylphenylsilanol, ethylisopropylphenylsilanol, n-butylethylphenylsilanol,
isobutylethylphenylsilanol, tert-butylethylphenylsilanol, methyldiphenylsilanol, ethyldiphenylsilanol,
n-propyldiphenylsilanol, isopropyldiphenylsilanol, n-butyldiphenylsilanol, isobutyldiphenylsilanol,
tert-butyldiphenylsilanol, phenylsilanetriol, 1,4-bis (trihydroxysilyl) benzene, 1,4-bis
(methyldihydroxysilyl) benzene, 1,4-bis (ethyldihydroxysilyl) benzene, 1,4-bis (propyldihydroxysilyl)
benzene, 1,4-bis (butyldihydroxysilyl) benzene, 1,4-bis (dimethylhydroxysilyl) benzene,
1,4-bis (diethylhydroxidesilyl) benzene, 1,4-bis (dipropylhydroxysilyl) benzene, 1,4-bis
(dibutylhydroxysilyl) benzene, and the like, and a compound represented by the Formula
(8) below.
(in the formula, R
7 is a monovalent organic group having a hydroxy group or a glycidyl group, R
8 and R
9 are independently an alkyl group having 1 to 5 carbon atoms. c is an integer of 1
to 10, and d is an integer of 0 to 2).
[0080] Among the above compounds, a compound represented by Formula (8) in particular further
improves the properties of adhesion to the substrate, and is therefore preferable.
[0081] Such a silane coupling agent includes hydroxymethyltrimethoxysilane, hydroxymethyltriethoxysilane,
2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 3-hydroxypropyltrimethoxysilane,
3-hydroxypropyltriethoxysilane, 4-hydroxybutyltrimethoxysilane, 4-hydroxybutyltriethoxysilane,
glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane,
2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,
4-glycidoxybutyltrimethoxysilane, 4-glycidoxybutyltrimethoxysilane, and the like.
[0082] The silane coupling agent having a hydroxy group or a glycidyl group in a molecule
is preferably a group further comprising a nitrogen atom together with a hydroxy group
or a glycidyl group, specifically, a silane coupling agent having an amino group and
an amide bond.
[0083] The silane coupling agent having an amino group includes bis (2-hydroxymethyl)-3-aminopropyltriethoxysilane,
bis (2-hydroxymethyl)-3-aminopropyltrimethoxysilane, bis (2-glycidoxymethyl)-3-aminopropyltriethoxysilane,
bis (2-hydroxymethyl)-3-aminopropyltrimethoxysilane, and the like.
[0084] The silane coupling agent having an amide bond includes a silane coupling agent having
an amide bond such as a compound represented by the formula below or the like.
X-(CH
2)
e-CO-NH-(CH
2)
f-Si(OR)
3
(in the formula, X is a hydroxy group or a glycidyl group, e and f are independently
an integer of 1 to 3, R is independently a methyl group, an ethyl group, or a propyl
group.)
[0085] The content of the silane coupling agent when used is preferably 0.1 to 20 parts
by mass with respect to 100 parts by mass of the (a) component, more preferably 0.3
to 10 parts by mass, and more preferably 1 to 10 parts by mass.
((2) dissolution accelerator)
[0086] A dissolution accelerator may be added in order to further accelerate the solubility
of (a) polybenzoxazole precursor in an alkaline aqueous solution. The dissolution
accelerator includes, for example, a compound having a phenolic hydroxyl group. By
being added to the photosensitive resin composition, the compound having a phenolic
hydroxyl group increases the dissolution rate of an exposed part at the time of development
using an alkaline aqueous solution, and can prevent the melting of the photosensitive
resin film when the photosensitive resin film is cured after pattern formation.
[0087] The compound having a phenolic hydroxyl group is not particularly limited, but is
preferably a compound having a relatively small molecular weight. Such a compound
includes o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, bisphenol
A, B, C, E, F, and G, 4,4',4"-methylidyne tris phenol, 2,6-[(2-hydroxy-5-methylphenyl)
methyl]-4-methylphenol, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene]
bisphenol, 4,4'-[1-[4-[2-(4-hydroxyphenyl)-2-propyl]phenyl]ethylidene] bisphenol,
4,4',4"-ethylidyne tris phenol, 4-[bis (4-hydroxyphenyl) methyl]-2-ethoxy phenol,
4,4'-[(2-hydroxyphenyl methylene) bis [2,3-dimethylphenol], 4,4'-[(3-hydroxyphenyl)
methylene] bis [2,6-dimethylphenol], 4,4'-[(4-hydroxyphenyl) methylene] bis [2,6-dimethylphenol],
2,2'-[(2-hydroxyphenyl) methylene] bis [3,5-dimethylphenol], 2,2'-[(4-hydroxyphenyl)
methylene] bis [3,5-dimethylphenol], 4,4'-[(3,4-dihydroxyphenyl) methylene] bis [2,3,6-trimethylphenol],
4-[bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) methyl]-1,2-benzenediol, 4,6-bis [(3,5-dimethyl-4-hydroxyphenyl)
methyl]-1,2,3-benzentriol, 4,4'-[(2-hydroxyphenyl) methylene] bis [3-methylphenol],
4,4',4"-(3-methyl-1-propanyl-3-ylidine) trisphenol, 4, 4', 4", 4"'-(1,4-phenylene
dimethylidyne) tetrakis phenol, 2,4,6-tris [(3,5-dimethyl-4-hydroxyphenyl) methyl]-1,3-benzenediol,
2,4,6-tris [(3,5-dimethyl-2-hydroxyphenyl) methyl]-1,3-benzenediol, 4,4'-[1-[4-[1-(4-hydroxyphenyl)-3,5-bis
[(hydroxy-3-methylphenyl)methyl]phenyl]-phenyl]ethylidene] bis [2,6-bis (hydroxy-3-methylphenyl)methyl]
phenol, and the like.
[0088] The content of the dissolution accelerator when used is preferably 1 to 30 parts
by mass with respect to 100 parts by mass of the (a) component from the viewpoint
of a development time and sensitivity, and is more preferably 3 to 25 parts by mass.
((3) dissolution inhibitor)
[0089] A dissolution inhibitor which is a compound that inhibits the solubility of the (a)
polybenzoxazole precursor in an alkaline aqueous solution can be contained. The dissolution
inhibitor serves to adjust the residual film thickness and the development time by
inhibiting the solubility of the (a) component. On the other hand, because acid that
is generated easily volatilizes, it is considered that the dissolution inhibitor is
not involved in the cyclodehydration reaction of the polybenzoxazole precursor.
[0090] A compound that can be used as a dissolution inhibitor is preferably diphenyliodonium
nitrate, bis (p-tert-butylphenyl) iodonium nitrate, diphenyliodonium bromide, diphenyliodonium
chloride, diphenyliodonium salts such as diphenyliodonium iodide.
[0091] The compounding amount of the dissolution inhibitor when used is preferably 0.01
to 50 parts by mass with respect to 100 parts by mass of (a) component from the viewpoint
of sensitivity and a development time, more preferably 0.01 to 30 parts by mass, and
further preferably 0.1 to 20 parts by mass.
((4) interfacial active agent or leveling agent)
[0092] Furthermore, the photosensitive resin composition according to the present invention
may additionally comprise an interfacial active agent or a leveling agent in order
to improve coatability (e.g. inhibition of striation (unevenness of thickness)) and
developability.
[0093] The interfacial active agent or the leveling agent includes, for example, polyoxyethyleneurarilether,
polyoxyethylenestearylether, polyoxyethyleneoleylether, polyoxyethyleneoctylphenolether,
and the like. Examples of commercially available products include trade names "Megafax
F171", "F173", and "R-08" (which are manufactured by Dainippon Ink and Chemicals,
Inc.), trade names "Fluorad FC430" and "FC431" (which are manufactured by Sumitomo
3M Limited), trade names "organosiloxane polymer KP341", "KBM303", "KBM403", and "KBM803"
(which are manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.
[0094] The content of the interfacial active agent or the leveling agent when used is preferably
0.01 to 10 parts by mass with respect to 100 parts by mass of the (a) component, more
preferably 0.05 to 5 parts by mass, and further preferably 0.05 to 3 parts by mass.
[Method of manufacturing pattern cured film]
[0095] A method of manufacturing a pattern cured film according to the present invention
comprises: a step (resin film forming step) of coating the positive-type photosensitive
resin composition on a substrate, drying the positive-type photosensitive resin composition,
and thereby forming a photosensitive resin film; a step (exposure step) of exposing
the photosensitive resin film to a predetermined pattern; a step (development step)
of developing the exposed photosensitive resin film by use of an alkaline aqueous
solution, and thereby forming a pattern resin film; and a step (heat treatment step)
of heat-treating the pattern resin film.
[0096] Each step is described below.
(Resin film forming step)
[0097] The substrate includes glass, semiconductor, a metal oxide insulator such as TiO
2 and SiO
2, silicon nitride, copper, a copper alloy, and the like. While there is no particular
limitation on the coating method, a spinner or the like can be used for coating.
[0098] Drying can be conducted by use of a hot plate, an oven, or the like. A heating temperature
is preferably 90 to 150°C, and more preferably 90 to 120°C in order to inhibit the
reaction between the (a) component and the (b) component from the viewpoint of ensuring
dissolution contrast. A heating time is preferably 30 seconds to 5 minutes. Thus,
it is possible to obtain a resin film in which the above-described resin composition
is formed into a film shape.
[0099] The thickness of the resin film is preferably 5 to 100 µm, more preferably 8 to 50
µm, and further preferably 10 to 30 µm.
(Exposure step)
[0100] In the exposure step, the photosensitive resin film can be exposed to a predetermined
pattern via a mask. Active rays to be applied include ultraviolet rays comprising
an i-line, visible rays, radiation rays, and the like, but are preferably the i-line.
As an exposure device, it is possible to use a parallel exposure machine, a projection
exposure machine, a stepper, a scanner exposure machine, or the like.
(Development step)
[0101] By performing a development treatment, it is possible to obtain a resin film in which
a pattern is formed (pattern resin film). Generally, when a positive type photosensitive
resin composition is used, the exposed part is removed with a developing solution.
[0102] An alkaline aqueous solution used as the developing solution includes sodium hydroxide,
potassium hydroxide, sodium silicate, ammonia, ethylamine, diethylamine, triethylamine,
triethanolamine, tetramethylammonium hydroxide, and the like. Tetramethylammonium
hydroxide is preferable.
[0103] The concentration of the alkaline aqueous solution is preferably 0.1 to 10 mass%.
[0104] The development time varies depending on the kind of (a) component used, but is preferably
10 seconds to 15 minutes, more preferably 10 seconds to 5 minutes, and further preferably
30 seconds to 4 minutes from the viewpoint of productivity.
[0105] An alcohol or an interfacial active agent may be added to the above developing solution.
The addition amount is preferably 0.01 to 10 parts by mass with respect to 100 parts
by mass of the developing solution, and more preferably 0.1 to 5 parts by mass.
(Heat treatment step)
[0106] By heat-treating the pattern resin film, it is possible to form a crosslinked structure
between the functional groups of the (a) component, between the (a) component and
the (b) component, or the like, and obtain a pattern cured film. Moreover, the (a)
component is a polybenzoxazole precursor, and can therefore cause a dehydration ring-closing
reaction by the heat treatment step, and can be corresponding polybenzoxazole.
[0107] The heating temperature is not particularly limited, but is preferably 250°C or less,
more preferably 230°C or less, and further preferably 200°C or less. Moreover, the
lower limit value of the heating temperature is not particularly limited either, but
is preferably 120°C or more, and more preferably 160°C or more. Within the above range,
it is possible to hold down the damage to the substrate or the device, produce the
device with a satisfactory yield, and achieve energy saving of a process.
[0108] The heating time is preferably 5 hours or less, and more preferably 30 minutes to
3 hours.
[0109] Within the above range, it is possible to sufficiently carry out a crosslinking reaction
or a dehydration ring-closing reaction. Moreover, the atmosphere of the heat treatment
may be atmospheric air or inert atmosphere of nitrogen or the like, but is preferably
nitrogen atmosphere from the viewpoint of being able to prevent the oxidation of the
pattern resin film.
[0110] The device used for the heat treatment step includes a quartz tube furnace, a hot
plate, rapid thermal annealing, a vertical diffusion furnace, an infrared curing oven,
an electron beam curing oven, a microwave curing oven, and the like.
[Cured product]
[0111] The cured product according to the present invention is a cured product of the positive-type
photosensitive resin composition according to the present invention, and can be a
cured product by applying the heat treatment step described above for the positive-type
photosensitive resin composition according to the present invention.
[0112] The cured product according to the present invention may be the pattern cured film
described above, or may be a cured film having no pattern.
[Electronic component]
[0113] The pattern cured film and the cured product manufactured by the method described
above can be used as an interlayer insulating film, a cover coat layer, or a surface
protection film. By use of the interlayer insulating film, the cover coat layer, the
surface protection film, or the like, it is possible to manufacture a highly reliable
electronic component such as a semiconductor device, a multilayer wiring board, and
various electronic devices.
[Process of manufacturing semiconductor device]
[0114] As an example of a process of manufacturing a pattern cured film according to the
present invention, a process of manufacturing a semiconductor device is described
with reference to the drawings. FIGS. 1 to 7 are schematic sectional views illustrating
a process of manufacturing a fanout package having a multilayer wiring structure,
and represent a series of steps from a first step to a seventh step. FIG. 8 is a schematic
sectional view of a fanout package having an under bump metal (UBM) free structure.
[0115] In these drawings, a semiconductor substrate 1 such as an Si substrate having a circuit
element (not shown) is covered with a protection film 2 such as a silicon oxide film
except for predetermined parts of the circuit element, and a first conductor layer
3 is formed on the exposed circuit element.
[0116] A film of a polyimide resin or the like as an interlayer insulating film 4 is formed
on the semiconductor substrate by a spin coat method or the like (first step, FIG.
1).
[0117] Next, a photosensitive resin layer 5 based on chlorinated rubber, phenol novolak,
or the like is formed on the interlayer insulating film 4 by the spin coat method.
Using the photosensitive resin layer 5 as a mask, a window 6A is provided by a known
method so that the interlayer insulating film 4 in the predetermined parts is exposed
(second step, FIG. 2). The interlayer insulating film 4 exposed in the window 6A part
is selectively etched by dry etching means using a gas such as oxygen or carbon tetrafluoride,
and a window 6B is formed. Then, the photosensitive resin layer 5 is completely removed
by use of an etching solution such that the first conductor layer 3 exposed from the
window 6B is not corroded and the photosensitive resin layer 5 is only corroded (third
step, FIG. 3).
[0118] Further, by use of a known method, a second conductor layer 7 is formed, and electrically
connected to the first conductor layer 3 (fourth step, FIG. 4). When a multilayer
wiring structure having three or more layers is formed, the steps described above
are repeated, and each layer is formed.
[0119] Next, a surface protection film 8 is formed by use of the positive-type photosensitive
resin composition according to the present invention as below. That is, the resin
composition of the present invention is subjected to coating by a spin coat method,
dried, irradiated with light from above a mask having a pattern drawn to form a window
6C in a predetermined part, and then developed with an alkaline aqueous solution,
whereby a pattern resin film is formed. Thereafter, this pattern resin film is heated,
and thus used as a pattern cured film of polybenzoxazole serving as the surface protection
film 8 (fifth step, FIG. 5). This surface protection film (pattern cured film of polybenzoxazole)
8 functions to protect the conductor layer from external stress, α-rays, and the like.
[0120] Furthermore, normally, after a metal thin film is formed on the surface of the surface
protection film 8 by a sputtering process, a plating resist is formed in accordance
with the window 6C by use of a known method, and a metal layer 9 called an under bump
metal (UBM) is precipitated in an exposed metal thin film portion by plating. Then,
the plating resist is stripped, and a metal foil film in a part other than the area
where the UBM 9 is formed is removed by etching to form a UBM (sixth step, FIG. 6).
Further, an external connection terminal 10 called a bump is formed on the surface
of the metal layer 9 (seventh step, FIG. 7). The metal layer 9 is formed for the purpose
of easing stress acting on the bump 10 and improving electrical connection reliability.
[0121] In recent years, from the viewpoint of manufacturing cost reduction, there has been
suggested a UBM free structure in which in order to omit the step of forming such
a metal layer 9 (UBM), the bump 10 is directly formed after the window 6C is formed
in the surface protection film 8. In the UBM free structure, in order to suppress
an electrical resistance increase due to the generation of an intermetallic compound,
it is necessary that the second conductor layer 7 to be connected to the bump 10 be
formed with a larger thickness than usual. Moreover, it is necessary that the stress
acting on the bump 10 be eased by the surface protection film 8 alone. Thus, it is
necessary to form a thicker surface protection film 8 in order to cover the second
conductor layer 7 formed with a large thickness, and enhance stress relaxation performance
(FIG. 8).
[0122] Therefore, in the UBM free structure, when the window 6C is formed in the previously
described surface protection film 8, it is necessary to coat with a thicker resin
film, and expose and develop the resin film.
EXAMPLES
[0123] Hereinafter, the present invention is more specifically described on the basis of
Examples and Comparative Examples. It is to be noted that the present invention is
not limited to Examples below.
Synthesis Example 1
[(a) component: synthesis of polybenzoxazole precursor (polymer I)]
[0124] 60 g of N-methylpyrrolidone was fed into a flask of 0.2 liters equipped with a stirrer
and a thermometer, and 13.92 g (38 mmol) of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane
was added and dissolved by stirring. Further, while the temperature was maintained
at 0 to 5°C, 7.48 g (28 mmol) of dodecanedioic acid dichloride and 3.56 g (12 mmol)
of 4,4'-diphenylether dicarboxylic acid dichloride were dropped for 10 minutes, and
then the solution in the flask was stirred for 60 minutes. The above-described solution
was poured into 3 liters of water, a precipitate was collected, and a resultant product
was washed with pure water three times and then depressurized, whereby a polybenzoxazole
precursor comprising the structure represented by Formula (1) was obtained (hereinafter,
referred to as a polymer I). The weight average molecular weight of the polymer I
was found to be 42,000 by gel permeation chromatography (GPC) in terms of standard
polystyrene, and the dispersity thereof was 2.0.
[0125] It is to be noted that the weight average molecular weight by the GPC was measured
by use of a solution including 1 ml of a solvent [tetrahydrofuran (THF) / dimethylformamide
(DMF) = 1/1 (volume ratio)] to 0.5 mg of a polymer.
[0126] A measurement device and measurement conditions are as below.
<Measurement device>
[0127] Detector: L4000 manufactured by Hitachi, Ltd.
UV Pump: L6000 manufactured by Hitachi, Ltd.
C-R4A manufactured by Shimadzu Corporation Chromatopac column: Gelpack GL-S300MDT-5×2
manufactured by Hitachi Chemical Co., Ltd.
<Measurement conditions>
[0128] Eluent: THF/DMF = 1/1 (volume ratio)
LiBr (0.03 mol/I), H
3PO
4 (0.06 mol/I)
Flow rate: 1.0 ml/min
Detector: UV270 nm
Synthesis Example 2
[(a) component: synthesis of polybenzoxazole precursor (polymer II)]
[0129] 7.48 g (28 mmol) of dodecanedioic acid dichloride and 3.56 g (12 mmol) of 4,4'-diphenylether
dicarboxylic acid dichloride used in Synthesis Example 1 were replaced by dodecanedioic
acid dichloride (40 mmol). Except for the above, synthesis was conducted as in Synthesis
Example 1, and a polybenzoxazole precursor comprising the structure represented by
Formula (1) was obtained (hereinafter, referred to as a polymer II). The weight average
molecular weight of the polymer II was 38,000, and the dispersity thereof was 2.0.
Synthesis Example 3
[(a') component: synthesis of polybenzoxazole precursor (polymer III)]
[0130] 60 g of N-methylpyrrolidone was fed into a flask of 0.2 liters equipped with a stirrer
and a thermometer, and 13.92 g (38 mmol) of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane
was added and dissolved by stirring. Then, while the temperature was maintained at
0 to 5°C, 11.86 g (40 mmol) of 4,4'-diphenylether dicarboxylic acid dichloride was
dropped for 10 minutes. Thereafter, the temperature was returned to room temperature,
and the solution in the flask was stirred for 3 hours. The above-described solution
was poured into 3 liters of water, a precipitate was collected, and a resultant product
was washed with pure water three times and then depressurized, whereby a polybenzoxazole
precursor was obtained (hereinafter, referred to as a polymer III). The weight average
molecular weight of the polymer III was 22,400, and the dispersity thereof was 3.2.
Examples 1 to 8, Reference Example 9, Comparative Examples 1 to 5
[Preparation of positive-type photosensitive resin composition]
[0131] The positive-type photosensitive resin compositions according to Examples 1 to 8,
Reference Example 9 and Comparative Examples 1 to 5 were prepared in accordance with
the components and the compounding amounts shown in Table 1. The compounding amounts
shown in Table 1 are the parts by mass of the (b) to (d), and (c') components with
respect to 100 parts by mass of each polymer which is the (a) component and/or (a')
component.
[0132] Each component used is as below.
<(a) component: polybenzoxazole precursor>
[0133]
- Polymer I: polymer I obtained in Synthesis Example 1
- Polymer II: polymer II obtained in Synthesis Example 2
[(a') component: polybenzoxazole precursor]
[0134]
- Polymer III: Polymer III obtained in Synthesis Example 3
[(b) component: crosslinking agent]
[0135]
- (b-1): compound represented by the structural formula below (manufactured by Sanwa
Chemical Co., trade name: NIKALAC MW-390)
- (b-2): compound represented by the structural formula below (manufactured by SANWA
CHEMICAL CO., LTD., trade name "NIKALAC MX-270")
[(c) component: photosensitive agent]
[0136]
- (c-1): compound represented by the structural formula below (manufactured by Daito
Chemix Corporation, trade name: TPPA428)
[(c') component: photosensitive agent]
[0137]
- (c-2): compound represented by the structural formula below (manufactured by Daito
Chemix Corporation, trade name: TPPA528)
[(d) component: solvent]
[Evaluation of positive-type photosensitive resin composition]
[0139] For the positive-type photosensitive resin compositions obtained in Examples 1 to
8, Reference Example 9 and Comparative Examples 1 to 5, sensitivity, resolution, adhesion
properties, and chemical resistance were evaluated in the manners shown below, respectively.
The results are shown in Table 1.
<Evaluation of sensitivity>
[0140] A silicon wafer was spin-coated with the obtained positive-type photosensitive resin
composition by use of a coating apparatus (manufactured by Tokyo Electron Co., Ltd.,
trade name: CLEAN TRACK ACT8), and the positive-type photosensitive resin composition
was dried for 3 minutes at 110°C, whereby a resin film having a thickness of 12 µm
was formed. The obtained resin film was exposed by use of an i-line stepper (manufactured
by Canon Inc., trade name: FPA-3000iW). After the exposure, the resin film was developed
at 23°C with 2.38 mass% of an aqueous solution of tetramethylammonium hydroxide (TMAH)
until the residual film ratio in an unexposed part became 75%. Then the resin film
was rinsed with water, and a pattern resin film was obtained. The exposure amount
when an exposure unit was opened was used as sensitivity, an evaluation was made as
below by the exposure amount. Less than 200 mJ/cm
2: A
200 mJ/cm
2 or more and less than 230 mJ/cm
2: B
230 mJ/cm
2 or more and less than 250 mJ/cm
2: C
250 mJ/cm
2 or more: D
<Evaluation of resolution>
[0141] Used as resolution was the minimum line width at which a pattern of a line-and-space
portion could be patterned without detachment and residue regarding the pattern resin
film obtained by exposure with the i-line stepper in a manner similar to that in the
evaluation of sensitivity described above.
<Evaluation of adhesion properties>
[0142] A copper wafer was spin-coated with the obtained positive-type photosensitive resin
composition by use of a coating apparatus (manufactured by Tokyo Electron Co., Ltd.,
trade name "CLEAN TRACK ACT8"), and the positive-type photosensitive resin composition
was dried for 3 minutes at 110°C, whereby a resin film having a thickness of 10 µm
was formed. The obtained resin film was heated for one hour at 175°C under nitrogen
atmosphere by use of a vertical diffusion furnace µ-TF (manufactured by Koyo Thermo
Systems Co., Ltd.), and a cured film (having a thickness of 8 µm after cured) was
obtained.
[0143] The obtained cured film was put in a pressure cooker (PCT) apparatus, and treated
under the conditions of 121°C, 2 atm, and RH of 100% for 100 hours (PCT treatment).
Thereafter, a cross cut test was performed on the cured film, and properties of adhesion
to the copper wafer were evaluated. The cross cut test was performed as below. First,
eleven parallel lines were drawn at intervals of 1 mm in each of the orthogonal vertical
and horizontal directions by use of a cutter guide in the center of the surface of
the cured film on the copper wafer, and grid-pattern cuts were made so that 100 square
cured films of 1 mm square were formed within 1 cm
2. Then a peeling test using a cellophane tape was performed on the grid pattern, and
the number of cured films of 1 mm square remaining on the copper wafer after the test
was counted. The case with 100 remaining cured films was evaluated as A, the case
with 50 to 99 remaining cured films was evaluated as B, and the case with 49 or more
remaining cured films was evaluated as C.
<Evaluation of chemical resistance>
[0144] A silicon wafer was spin-coated with the obtained positive-type photosensitive resin
composition by use of a coating apparatus (manufactured by Tokyo Electron Co., Ltd.,
trade name: CLEAN TRACK ACT8), and the positive-type photosensitive resin composition
was dried for 3 minutes at 110°C, whereby a resin film having a dry film thickness
of 12 µm was formed. The obtained resin film was subjected to exposure 1.2 times that
in the above-described evaluation of sensitivity by use of an i-line stepper (manufactured
by Canon Inc., trade name: FPA-3000iW), and developed until the residual film ratio
in an unexposed part became 75%. Thus, a pattern resin film was obtained.
[0145] The pattern resin film obtained as described above was heated for one hour at 200°C
under nitrogen atmosphere by use of a vertical diffusion furnace µ-TF (manufactured
by Koyo Thermo Systems Co., Ltd.), and a pattern cured film was obtained. The obtained
pattern cured film was dipped in a resist stripping solution (manufactured by Dynaloy,
LLC, trade name: Dynastrip 7700) for 120 minutes at 70°C, and the surface of the pattern
cured film was then observed with an optical microscope. From the difference in film
thickness before and after dipping in the chemical solution, a pattern cured film
having a thickness change of less than 5% due to dipping was evaluated as A, a pattern
cured film having a thickness change of 5% or more and less than 10% was evaluated
as B, and a pattern cured film having a thickness change of 10% or more was evaluated
as C. Further, a pattern cured film in which the resist stripping solution was impregnated
in the pattern portion, and a pattern cured film in which the pattern portion was
stripped due to the dipping were evaluated as D (not a practical level).
[Table 1]
|
Examples |
Comparative Examples |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9* |
1 |
2 |
3 |
4 |
5 |
(a) component |
Polymer I |
100 |
100 |
100 |
100 |
100 |
100 |
90 |
0 |
100 |
0 |
100 |
0 |
50 |
50 |
Polymer II |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
100 |
0 |
0 |
0 |
0 |
0 |
0 |
(a') component |
Polymer III |
0 |
0 |
0 |
0 |
0 |
0 |
10 |
0 |
0 |
100 |
0 |
100 |
50 |
50 |
(b) component |
b-1 |
25 |
20 |
30 |
12 |
20 |
20 |
25 |
25 |
0 |
25 |
0 |
0 |
0 |
0 |
b-2 |
0 |
0 |
0 |
12 |
5 |
0 |
0 |
0 |
25 |
0 |
25 |
20 |
15 |
25 |
(c) component |
c-1 |
10 |
10 |
10 |
10 |
10 |
15 |
10 |
10 |
10 |
10 |
0 |
0 |
0 |
0 |
(c') component |
c-2 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
10 |
10 |
10 |
10 |
(d) component |
BLO |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
160 |
Sensitivity |
A |
A |
B |
A |
A |
A |
B |
A |
A |
B |
C |
D |
D |
D |
Resolution (um) |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
2 |
5 |
5 |
5 |
5 |
5 |
5 |
Adhesion properties |
A |
A |
A |
A |
A |
A |
B |
A |
C |
C |
C |
C |
C |
C |
Chemical resistance |
A |
A |
A |
A |
A |
A |
A |
A |
B |
D |
D |
D |
D |
C |
[0146] From Table 1, it can be seen that the positive-type photosensitive resin compositions
according to Examples 1 to 8 have satisfactory sensitivity and resolution. It can
also be seen that the positive-type photosensitive resin compositions according to
Examples 1 to 8 have satisfactory adhesion properties even when cured at a low temperature
of 175°C, and have satisfactory chemical resistance even when cured at a low temperature
of 200°C. Furthermore, Reference Example 9 is a system only using (b-2) as the (b)
component, but it can be seen that Reference Example 9 has favorable sensitivity and
chemical resistance as compared with Comparative Examples. On the other hand, it can
be seen that Comparative Examples 1 to 5 have poor chemical resistance.
[Industrial Applicability]
[0147] The photosensitive resin composition according to the present invention can be used
in a semiconductor device, a multilayer wiring board, and an electronic component
such as various electronic devices.
[0148] While several embodiments and/or examples according to the present invention have
been described above in detail, those skilled in the art can easily make numerous
modifications to these illustrative embodiments and/or examples substantially without
departing from the scope of the appended claims.